Self-sealing chalk valve

ABSTRACT

A cup-shaped molded rubber valve body having a diaphragm with a diametric slit, said valve body being forced into an aperture in a rigid chalk confining shell, and expanding into and around the edges of said aperture, said shell embodying a dihedral seat bordering said aperture which bends said valve about an axis at a right angle to said slit, thereby biasing the lips of said slit together causing said valve to close when a chalk-injecting nozzle has been withdrawn from said valve.

llnited States Patent Inventor Robert K. Campbell 2985 Newport Blvd., Costa Mesa, Calif. 92627 Appl. No. 3,854

Filed Jan. 19, 1970 Patented Nov. 23, 1971 SELF-SEALING CHALK VALVE 4 Claims, 6 Drawing Figs.

1.1.8. Cl 137/525.l, 220/44 llnt. Cl Fl6k 15/14 Field of Search 137/525. 1, 525.3, 525; 222/490; 220/44, 24.5, 90; 217/104; 242/ 100, 848

References Cited UNITED STATES PATENTS 6/1897 Leidich 137/525.1

Bent

OShei Kolos Chupa Primary ExaminerSamuel B. Rothberg Assistant E.\'aminerWilliam H. Wright Ar!orney Dana F. Keech ABSTRACT: A cup-shaped molded rubber valve body having a diaphragm with a diametric slit, said valve body being forced into an aperture in a rigid chalk confining shell, and expanding into and around the edges of said aperture, said shell embodying a dihedral seat bordering said aperture which bends said valve about an axis at a right angle to said slit, thereby biasing the lips of said slit together causing said valve to close when a chalk-injecting nozzle has been withdrawn from said valve.

PATENTEDN 2 I97! 3.621.876

lNl/EN 70/? ROBERT K. CAMPBELL ATTORNEY.

SELF-SEALING CHALK VALVE SUMMARY OF INVENTION The present invention relates primarily to chalkline reels although it is applicable in many other arts in which flexible valves are employed.

A chalkline reel particularly suitable for employing the valve of the present invention is disclosed in my U.S. Pat. No. 3,311,3l9 which issued on Mar. 28, 1967. Each such reel includes essentially a thin metal shell for enclosing a body of powdered chalk, a reel on which is wound a nylon chalkline, a handle connected to said reel and disposed outside of said shell for rotating said reel manually, a valved opening in said shell through which said line may pass so that a limited amount of chalk is embedded in said line as it is pulled from said shell.

Said shell is also provided with a valve opening for replenishing the supply of chalk in said shell and the present invention has for its principal object the provision of a rubber valve governing the admission of powdered chalk to the interior of said shell.

It is another object of the invention to provide such a chalk valve through which chalk may be injected into said chalkline reel shell by merely penetrating the valve with a nozzle provided on a bellow-type plastic bottle filled with powdered chalk.

It is another particular object of the invention to provide such a valve which will effectively close automatically as soon as said nozzle is withdrawn from penetrating relationship with the valve.

Yet a further object of the invention is to provide such a valve'which will attain the foregoing objects by virtue of a distortion of the valve member by the shape given the seat surrounding the chalk receiving aperture in the chalkline reel shell which shape biases the lips of a split diaphragm in the valve towards each other so that these lips quickly return to tightly closed relation as soon as the chalk injecting nozzle is withdrawn from between said lips.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged plan view of a preferred embodiment of the valve of the present invention properly installed in an aperture provided therefor in the shell of a chalkline reel.

FIG. 2 is a bottom plan view of FIG. 1.

FIG. 3 is a vertical sectional view taken on the line 3-3 of FIG. 2 and illustrating the distortion produced in the valve of the invention by a dihedral seat embodied with the reel shell in which the mounting aperture of the invention is provided.

FIG. 4 is a vertical sectional view taken on the line 4-4 of FIG. 2 and showing the valve of the invention just prior to itsbeing inserted in the valve-receiving aperture thereof and thus illustrating said valve before it is distorted by insertion into said aperture as shown in FIG. 3. This view also clearly shows the dihedral character of the upper and lower surfaces of the chalkline reel shell in the areas bordering the valve body mounting aperture of the shell.

FIG. 5 is a vertical sectional view taken on the line 5-5 of FIG. 2 and diagrammatically showing the biasing forces set up in said valve which press opposing lips of the valve slit of the diaphragm thereof together after the valve is installed in the aforesaid aperture in said shell. This view also diagrammatically illustrates the nozzle of a conventional chalk supply bottle axially oriented with said valve as when advancing the same to penetrate said valve with said nozzle for introducing a fresh supply of powdered chalk to the chalkline reel equipped with said valve.

FIG. 6 is a bottom plan view of FIG. 5 showing the manner in which the lips of the slit in the valve diaphragm are parted by said nozzle during the introduction of powdered chalk from said nozzle through said valve and into said reel.

DESCRIPTION OF THE PREFERRED EMBODIMENT The valve 10 of the present invention includes a valve body 11 and a dihedral seat 12 which surrounds a valve body receiving aperture 13 which is formed in a cast aluminum wall 14 which is part of a shell 15 of a chalkline reel (not shown).

Valve body 11 is cup-shaped and symmetrically molded of rubber about an axis A--A as shown in FIG. 4 to provide a central semispherical recess 16, a conical bottom surface 17 which terminates peripherally in a narrow flange 18 which is spaced downwardly a short distance from a wider upper peripheral flange 19 by a narrow cylindrical external face 20. The face 20 forms the bottom of an annular groove 25 formed by said face and the flanges l8 and 19.

The valve body 11 forms a cup the interior surface of which is formed by semispherical recess 16, this cup having a bottom wall 26 which is bounded on the top by recess 16 and on the bottom by conical bottom surface 17. The bottom wall 26 has a diametral slit 27 formed therein, the ends 28 of which are indicated by broken lines in FIGS. 3 and 4. This slit 'may be formed with a sharp knife or razor blade and divides the material of the wall 26 into two lips 29 which are normally juxtaposed in contact with each other even when the valve body 11 is under no restraint as this body is shown in FIG. 4 before it is assembled with the shell 15.

The aperture 13 is round and has a diameter which is the same as the diameter of the cylindrical external face 20 of the valve body 11. The wall 14 is flat, in the area in which the aperture 13 is formed, and shoulders 30 and 31 are fonned upwardly and downwardly respectively from the material of said wall in the areas bordering the upper and lower ends of said aperture. The top face of the upper annular shoulder 30 is bent about a diametric axis 32 to form a shallow concave dihedral angled face 33 on said shoulder. The lower annular shoulder 31 is shaped in an opposite manner to form thereon a convex dihedral angled face 34. The axial length of the circular aperture 13 in wall 14 at all points therein is equal to the axial length of annular groove 25 in the valve body 11.

To assemble the valve body 11 upon the wall 14, the valve body is aligned with the aperture 13 as shown in FIG. 4 and in the presence of a lubricant such as water is pushed axially through the aperture 13 until the wall 14 is received in the annular groove 25 with the narrow peripheral flange l8 resting upwardly against the dihedral convex angled face 34 and with the wider upper peripheral flange l9 resting downwardly against and conforming to the dihedral concave angled face 33 as clearly shown in FIG. 3. This assembly, it is to be noted, is made always with the diametral slit 27 of the valve body 11 disposed at right angles with the diametric axis 32 of the dihedral concave face 33 (see FIG. 4).

The assembly of the valve body 11 is this manner on the wall 14 bends said valve body about diametric axis 32 of the wall 14 which twists said body so as to pressurally bias the lips 29 on opposites of the diametral valve slit 27 into tightly closed contact with each other. The biasing forces thus created are indicated by the arrows 35 in FIG. 5. This figure also illustrates a nozzle 40 of a flexible plastic bottle 41 containing powdered chalk and poised in alignment with the valve 10 for the insertion of the tip of said nozzle through the valve as shown in FIG. 6 to part the lips 29 and secure entrance to the shell 15 for replenishing the supply of chalk in said shell. As soon as this function has been completed the nozzle 40 is withdrawn from between the lips 29, whereupon said lips are snapped quickly into compressed face-to-face, closed relation as shown in FIG. 5 by the operation of the biasing forces 35.

While the invention preferably includes the formation on the wall 14 of a lower annular shoulder 31 having a dihedral convex angled face 34 which cooperates with the upper an gular shoulder 30 and the dihedral concave angled face 33 provided thereby in bending the valve body 11 about diametric axis 32 as shown in FIG. 3, this bending action may be produced alone by the provision of an upper annular shoulder 30 with its dihedral concave angled face 33 and cementing the valve body 11 in place so that the upper peripheral flange 19 of said valve body adheres to and conforms with the dihedral concave angled face 33 so as to flex the valve body 11 into a dihedral shape as shown in FIG. 3.

lclaim:

1. In combination:

a cup-shaped molded rubber valve body having a mounting rim and a bottom providing a diaphragm with a diametric slit dividing said diaphragm into two juxtaposed lips. an external annular groove being formed peripherally in said rim to provide upper and lower flanges bordering said groove;

a rigid wall having a circular aperture into which said body is adapted to be pressed to mount said body in said aperture, said groove concentrically closely fitting said aperture when said body is so mounted;

said wall being provided with surfaces bordering said aperture which operate when said body is inserted in said aperture to conform therewith, to bend said body toward said slit about a diametral axis disposed crosswise of said slit to bias said lips into face-to-face pressural contact with each other to cause said slit to be positively closed by said forces when an element separating said lips is removed from between these.

2. A combination as recited in claim I wherein shoulder means are provided on said rigid wall bordering said aperture, said means presenting a flat face forming a shallow dihedral angle to one of said peripheral flanges on said valve body so as to bend said valve body about a central transverse axis disposed crosswise to the plane of said slit to set up forces in said valve body biasing said lips into pressural contract with each other.

3. A combination as recited in claim 2 wherein two shoulder means. as aforesaid, are provided, one on the upper face ofsaid wall and one on the lower face thereof said two shoulder means forming approximately parallel dihedral angular faces and acting respectively on the upper and lower flanges of said valve body to bend said body about a transverse axis close to the apices ofsaid angles.

4. A combination as recited in claim 2 wherein said shoulder means are annular in character thus extending entirely around said aperture, and the apex ofsaid dihedral angle is diametrally related to said aperture. 

1. In combination: a cup-shaped molded rubber valve body having a mounting rim and a bottom providing a diaphragm with a diametric slit dividing said diaphragm into two juxtaposed lips, an external annular groove being formed peripherally in said rim to provide upper and lower flanges bordering said groove; a rigid wall having a circular aperture into which said body is adapted to be pressed to mount said body in said aperture, said groove concentrically closely fitting said aperture when said body is so mounted; said wall being provided with surfaces bordering said aperture which operate when said body is inserted in said aperture to conform therewith, to bend said body toward said slit about a diametral axis disposed crosswise of said slit to bias said lips into face-to-face pressural contact with each other to cause said slit to be positively closed by said forces when an element separating said lips is removed from between these.
 2. A combination as recited in claim 1 wherein shoulder means are provided on said rigid wall bordering said aperture, said means presenting a flat face forming a shallow dihedral angle to one of said peripheral flanges on said valve body so as to bend said valve body about a central transverse axis disposed crosswise to the plane of said slit to set up forces in said valve body biasing said lips into pressural contract with each other.
 3. A combination as recited in claim 2 wherein two shoulder means, as aforesaid, are provided, one on the upper face of said wall and one on the lower face thereof, said two shoulder means forming approximately parallel dihedral angular faces and acting respectively on the upper and lower flanges of said valve body to bend said body about a transverse axis close to the apices of said angles.
 4. A combination as recited in claim 2 wherein said shoulder means are annular in character thus extending entirely around said aperture, and the apex of said dihedral angle is diametrally related to said aperture. 